I remember some movie about Indiana basketball with Gene Hackman a long time ago. Well, the title also applies to my recent fascination and love with hoop springs. Most of the pince-nez you see on eBay and other sites are the fingerpiece variety (springs in the nose guards). Hoop springs predate the fingerpiece and they have a noble history. Woodrow Wilson and FDR wore hoop springs as did many members of their administrations.
The hoop spring has many amazing properties. First and foremost is the simplicity of the design. Unlike a fingerpiece, there are very few parts and someone with limited skill (such as LeDandy) can completely disassemble and put back together a hoop sping in a few minutes. The hoop spring featured below shows the parts. Starting at 12 o'clock and going counterclockwise, you have the bridge, screw, strap and nose guard.
Second, another interesting property is that many hoop springs have interchangeable parts. It is easy to swap out parts as the dimensions seem to be quite uniform. Are the nose guards uncomfortable? It is easy to swap out this part while still keeping the rest of the hoop spring.
Finally, the design itself is flattering to the appearance for most people. The high hoop on this hoop spring elongate the nose in an appealing way.
One useful tip if you do acquire an antique hoop spring. If the screws are not movable, soak the mounting in WD-40 overnight. You should have no problem the following day removing the screws. Enjoy.